Device for forming a compressed rod of tabacco



OCR 21, 1969 F. wlLDE ETAL. 3,473,537

DEVICE FOR FORMING A CMPRESSED ROD 0F TOBACCO Filed oct. 5, lese FiG. 2

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3 9B w INVENTORS n I6 n FRIEDRICH WILDE JOHANNES HERRMANN United StatesPatent O 3,473,537 DEVICE FUR FJRMHNG A COlt/IPRESSED RUB F TQBACCFriedrich Wilde and .iohannes Herrmann, Dresden, Germany, assignors toVEB Tabakund lndustrieanaschinen Dresden, Dresden, Germany Filed Get. 5,1966, Ser. No. 584,409 Int. Cl. A24c 5/.78

U5. Cl. 131-84 5 Claims ABSTRACT 0F THE DISCLGSURE A device for formingstrands of tobacco fibers into a tobacco rod including a `conduit on thecircumference of a suction wheel in which the conduit is foraminous. Therecesses are disposed at spaced locations in the conduit whereby thetobacco fibers are slowed down in the area of said recesses to therebybuild up the same into a tobacco rod.

The device further has a foraminous belt located adjacent to the tobaccostream of the suction wheel.

The invention relates generally to a device for forming a compressed rodof tobacco and in particular to a rod which is densied at predeterminedportions. This rod of tobacco is made from a tobacco stream.

When making cigarettes from a rod of tobacco as indicated above,difticulties exist in maintaining an even amount of tobacco at thelocation where the rod is cut into cigarette lengths. It has beenalready suggested to provide more tobacco fillings at this location. Forthis purpose, different devices are known to solve the problemsinvolved.

All the devices which are presently utilized to achieve more tobaccofilling at that tobacco rod portion which will be cut to establish anend of the cigarette operate on the principal of either addingsuperfluous tobacco to the portion to be cut or trimming and removingtobacco from those portions of the cigarette which are not to be cutwith the result that when the tobacco is cut, the rod forming andwrapping procedure densities the tobacco of the cigarette at the endsthereof and establishes the desired results. These devices aredisadvantageous in that the fibrous tobacco structure is shortened dueto the trimming and cut. Besides, all these mechanical measures likeseparating, adding and displacing the tobacco are rather uneconomical,especially with high velocity tobacco streams. These methods areunsatisfactory because of rather high fluctuations in the attaineddistribution of the tobacco during the trimming process.

It is therefore an object of the invention to overcome theabove-mentioned shortcomings, by forming a tobacco rod provided withpredetermined densiiied portions and to achieve this desired result byemploying simple means which simultaneously achieve a higher speed.

It is a further object of the invention to form measured densificationson the dened places of a tobacco rod without shortening the tobaccofibers.

In accordance with the invention these objects are achieved in that thetobacco portions in the tobacco stream are guided at a high speed into agroove. The groove is provided with enlarged recesses which are disposedin even distances from each other. The tobacco portions are slowed downand positioned in the groove by removing air therefrom, so that thetobacco portions iill the inner chamber of the groove. Subsequently, thetobacco rod whose cross-sectional area is increased at predeterminedplaces will be transferred to a known l cigarette forming device andfinally densied with a higher density at the end portions of thecigarettes.

3,473,537 Patented Oct. 2l, 1969 The inventive device comprises achannel disc provided with a circumferentially arranged conduit, thecross section of which is selectively varied by recesses, formed in aperforated base circumferentially surrounding the disc and forming awall portion of the conduit. The advantage of the inventive deviceconsists in that tobacco densifications of desired volume and atpredetermined positions along the rod may be formed automatically, by asimple reliance of pneumatic pressure axially directed forcing thetobacco stream to till the predefined volume, without employingmechanical means or using a superfluous quantity of tobacco. This simpleprocedure operates reliably even at the highest possible rod formingspeeds, due to the momentum of the tobacco stream, so that the knownadvantages of the cigarette end compaction are achieved with lessmechanical means by simultaneously increasing the production output ofthe machine and by lowering the construction expenses.

The invention will be more clearly understood from the followingdescription of a specific embodiment of the invention together with theaccompanying drawings, in which:

FIG. l is a vertical sectional view of a rod forming device according tothe invention;

FIG. 2 is a sectional view taken alon-g line II-II of FIG. 3; and

FIG. 3 is an enlarged sectional view of the guide plate and theseparating wall, taken along line lI-II of FIG. l, with some partsomitted for clarity.

With respect to the subject of the invention it should be noted thatnumerous embodiments for these devices are possible. However, apreferred embodiment is used as shown in the accompanying drawings inaccordance with the inventive method. With reference to FIG. 1 of thedrawing, it is seen that radial depressions are formed in a rotatinggrooved disc 1. Channel disc 1 is in communication with a supply conduit2, a portion of this conduit being shown in FlG. 1, through which atobacco stream is guided. Conduit 2 extends tangentially of a -groove 3,which is formed on the circumference of channel disc 1. The base 18 ofgroove 3 is interspersed with line holes and is provided with aplurality of enlarged rounded recesses 4 disposed intermittently aboutits circumference. A

cigarette paper web 5 is guided opposite and parallel with respect toconduit 2 which receives the tobacco rod and guides the same into acigarette forming device 6. Channel disc 1 is encompassed by perforatedband 8 which is guided over rollers 7, and extends from conduit 2 tocigarette paper web 5 so that perforated band 8 forms a closed conduit 3with the ange portions 17 of disc 1 and the perforated base 18. Member19 is a stationary block in the form of a semi-circular disc which isdisposed with its surface adjacent the inner side of base 18. Thiselement 19 closes the perforations in base 18 and thereby serves toclose the left half of the interior of the suction wheel as seen in FIG.2 so that only the right hand half of the interior thereof may comprisea suction chamber. An adjustable partition 9 is provided within theactive part and separates the vacuum chamber into a starting zone 10 andend zone 11. The pressure which is present in starting zone 10 and endzone 11 is adjustable by means of a movable baflle plate 13. A vacuumconduit 12 for producing a vacuum within the vacuum chamber of the disc1 is connected to a vacuum pressure source (not shown).

The operation of the device is as follows:

The tobacco stream which is introduced into the rod groove 3 at highvelocity is of low density. At the end of zone 11 where this streamcollides with the already formed but uncut tobacco rod which is movingat the considerably lower speed of the channel wheel which is driven byconventional means which are diagrammatically shown at 30. The tobaccostream density is increased until it corresponds to the tobacco roddensity. This occurs before the stream is transferred intocigarette-paper web 5.

Suction pipe 12 acts to create a vacuum in the space defined by thesuction pipe 12 and suction chamber 15 inside the grooved disk 1. Thisspace is divided into two portions by the positioning of partition 9 andbaffle plate 13. Partition 9 effectively divides the suction chamber 15into two portions as can be seen in PIG. 2. As can be seen in thedrawings baie plate 13 and partition 9 are hinged on shaft 22 and haveportions which effectively divide the suction pipe 12 into two portions.Therefore, if in FIG. 2, baffle plate 13 is positioned in an upwardvertical direction and if partition 9 is positoned rghtwardlyhorizontally, it can be seen that the suction pipe 12 and suctionchamber 15 have been so divided so that 3A of the suction acts onsection 11 an 1A of the suction acts on volume 10. Therefore a differenteffective pressure is maintained in each section (10, 11).

The effective pressure in each of these zones and the angular extent ofthe disk over which it will act are predetermined based on factors to besubsequently discussed. Once having been so determined, the partition 9is rigidly connected, at this pre-determined position, to the shaft bymeans of a pin 23. Shaft 22 is clamped by means of knurled nut 25against the end faces of the bushing 24, while at the same time the endfaces of the hinge parts of baffle plate 13 are pressed against the endfaces of the hinge parts of partition 9. Bushing 24 is pressed tightlyinto the front bore of suction pipe 12. This effects a stationaryplacement of baille plate 13 and partition 9 at pre-determinedpositions.

The suction effect in Zone 10 is designed to be less than the vacuumeffect of zone 11. As the tobacco stream enters conduit 2 it is sloweddown in zones 10 and 11 as a result of the vacuum effect of zones 10 and11 and because of frictional considerations. This effect results in theslowdown in two ways: first, the tobacco stream is pulled against theperforated base 18 and this increases the friction between the streamand the disk 1, and secondly, as the density is thereby increasedfriction within the tobacco stream is increased. This effect, therefore,results in a velocity gradient as the stream progresses towards thecigarette forming device 6. As the stream approaches the end of zone 11the stream has a velocity greater than the tobacco rod downstream of theforming device. The band perforations permit air to flow radiallyinwardly through the tobacco shreds in the conduit, through theperforated base 118 and into the suction chamber 15. This results in thecomplete filling of the total cross-sectional area 16 formed by rodgroove 3, perforated band 8 and flanges 17. The recesses 4, which arefilled with a larger quantity of tobacco are so arranged that they formthe end portions of the cigarette so that upon the cutting of thecigarete the cigarete will be densified at the ends thereof.

In accordance with the foregoing described device, it is apparent thatbecause of the recesses 4 formed in rod lgroove 3 and because of thepneumatic construction, a tobacco rod may be formed with defined anddesired densications at predetermined locations without shortening thefibrous structure of the tobacco.

What is claimed is:

1. A device for forming tobacco fibers into a tobacco rod to be suppliedto a cigarette forming apparatus, said rod having portions thereof eachhaving an increased quantity of fibers therein than that in theremainder thereof, comprising a conduit for receiving an air current ata predetermined flow rate means for feeding said tobacco into said aircurrent to form a tobacco stream, a rotating suction wheel having acircumferential groove and a foraminous periphery and having depressionsradially directed therein, a foraminous belt located adjacent to theexterior of said circumferential groove of said wheel forming a closedconduit therewith, and means for applying a vacuum to the periphery ofsaid Suction wheel for withdrawing air from said tobacco stream, saidtobacco stream having a greater velocity than said channel wheelconduit, said tobacco rod having the same Velocity as said channel wheelconduit, said tobacco stream colliding into said tobacco rod whereby atobacco rod is formed having predetermined densifications spaced alongits length.

2. A device as claimed in claim 1 wherein said means for applying avacuum to said suction wheel includes a vacuum chamber means.

3. A device as claimed in claim 2 wherein said conduit is directed tothe periphery of said suction wheel and coupled to said circumferentialgroove, and said vacuum applying means is located at the side of saidgroove nearer to said vacuum chamber means.

4. A device as claimed in claim 1 wherein said depressions are equallyspaced from one another.

5. A device as claimed in claim 4 wherein said depressions are arcuateto thereby insure a smooth buildup or' said tobacco rod.

References Cited UNITED STATES PATENTS 1,721,117 7/1929 Hopkins.2,236,579 4/ 1941 Rundell. 2,290,896 7/ 1942 Stein. 2,969,104 1/1961Schubert et al. 3,074,413 1/ 1963 McArthur. 3,094,127 6/ 1963 Gamberini.3,244,184 4/ 1966 Petr.

FOREIGN PATENTS 941,854 11/ 1963 Great Britain.

JOSEPH S. REICH, Primary Examiner

